giles
d1a4616ac4
Some checks failed
Test, Build, and Deploy / test-build-deploy (push) Failing after 26s
BFS-based 2-coloring of an undirected graph:
edges (undirected):
0-1 0-3 1-2 1-4 2-5 3-4 3-6 5-6
Partition: {0, 2, 4, 6} vs {1, 3, 5} (no odd cycles)
Returns count of color-0 vertices (4) on success, -1 on odd-cycle
detection.
Tests Queue-based BFS with a source-loop wrapper for disconnected
graphs, `1 - color.(u)` toggle, color-equality conflict check
on already-colored neighbors.
164 baseline programs total.
40 lines
803 B
OCaml
40 lines
803 B
OCaml
let is_bipartite n adj =
|
|
let color = Array.make n (-1) in
|
|
let ok = ref true in
|
|
let q = Queue.create () in
|
|
for src = 0 to n - 1 do
|
|
if color.(src) = -1 then begin
|
|
color.(src) <- 0;
|
|
Queue.push src q;
|
|
while not (Queue.is_empty q) do
|
|
let u = Queue.pop q in
|
|
List.iter (fun v ->
|
|
if color.(v) = -1 then begin
|
|
color.(v) <- 1 - color.(u);
|
|
Queue.push v q
|
|
end else if color.(v) = color.(u) then
|
|
ok := false
|
|
) adj.(u)
|
|
done
|
|
end
|
|
done;
|
|
let zeros = ref 0 in
|
|
for i = 0 to n - 1 do
|
|
if color.(i) = 0 then zeros := !zeros + 1
|
|
done;
|
|
if !ok then !zeros else -1
|
|
|
|
;;
|
|
|
|
let n = 7 in
|
|
let adj = [|
|
|
[1; 3];
|
|
[0; 2; 4];
|
|
[1; 5];
|
|
[0; 4; 6];
|
|
[1; 3];
|
|
[2; 6];
|
|
[3; 5]
|
|
|] in
|
|
is_bipartite n adj
|